Bacterial diversity in Philippine fermented mustard (burong mustasa) as revealed by 16S rRNA gene analysis

2011 ◽  
Vol 2 (4) ◽  
pp. 263-271 ◽  
Author(s):  
L.L. Larcia II ◽  
R. Estacio ◽  
L.M. Dalmacio

Previous studies on the bacterial profile of burong mustasa, a traditional Philippine fermented food, had been conducted using culture-dependent techniques. Since these methods may underestimate the total microbiota of a sample, a culture-independent study was done to determine the bacterial diversity in burong mustasa through molecular biology techniques. Bacterial DNA was isolated from fermented mustard samples at different stages of fermentation. The isolated genomic DNA was amplified by PCR using specific primers for the 16S ribosomal RNA gene (16S rDNA). The 1.5 kb amplicons obtained were subjected to nested PCR using primers for the internal variable region of the 16S rDNA. The 585 bp nested PCR amplicons were then subjected to denaturing gradient gel electrophoresis (DGGE) to separate the different bacteria present in each sample. Distinct and unique bands in the DGGE profile were excised, reamplified, purified and sequenced for bacterial identification. Molecular cloning of the 1.5 kb 16S rDNA was also performed using the pGEM-T Easy Vector System. The cloned gene was sequenced for bacterial identification. The identified microbiota in burong mustasa at different stages of fermentation include lactic acid bacteria and several uncultured bacteria (initial up to the final stages); acetic acid bacteria (middle stage); and Streptobacillus and Fusobacterium species (initial stage). The potential probiotic bacteria found in burong mustasa are Weissella and Lactobacillus.

2011 ◽  
Vol 2 (4) ◽  
pp. 273-281 ◽  
Author(s):  
L.M. Dalmacio ◽  
A.K. Angeles ◽  
L.L. Larcia ◽  
M. Balolong ◽  
R. Estacio

The bacterial population in several Philippine fermented food preparations was assessed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) of the 16S rRNA gene (16S rDNA). Genomic DNA was isolated directly from alamang (fermented shrimp paste), burong isda (fermented fish and rice), burong hipon (fermented shrimp and rice), burong mustasa (fermented mustard leaves), tuba (sugar cane wine), suka (vinegar) and sinamak (spiced vinegar) using one of two protocols, namely – MoBio DNA Extraction Kit procedure and a cetyltrimethylammonium bromide-based method. Samples recalcitrant to both methods underwent enrichment in three culture broths prior to DNA isolation. Isolated DNA was amplified using nested primer pairs targeting the bacterial 16S rDNA. PCR products were subjected to DGGE to elucidate the bacterial diversity in each fermented food. 16S rDNA sequence analyses revealed that lactic acid bacteria (LAB) and acetic acid bacteria (AAB) were dominant in the food samples. The LAB identified were Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus panis, Lactobacillus pontis and Weissella cibaria. Identified AAB were Acetobacter pomorum, Acetobacter ghanensis, Acetobacter orientalis, and Acetobacter pasteurianus. Among these, L. fermentum, L. plantarum and W. cibaria are established probiotic bacteria, while L. panis and L. pontis are potential probiotic bacteria. This finding would increase the appeal and significance of local fermented foods to consumers. Furthermore, the majority of the identified bacteria in the study have not been reported before in culture-dependent studies of similar food preparations. As such, some of the bacterial 16S rDNA obtained were cloned to have an initial partial bacterial 16S rDNA library for Philippine fermented foods.


2003 ◽  
Vol 69 (11) ◽  
pp. 6380-6385 ◽  
Author(s):  
R. Temmerman ◽  
L. Masco ◽  
T. Vanhoutte ◽  
G. Huys ◽  
J. Swings

ABSTRACT The taxonomic characterization of a bacterial community is difficult to combine with the monitoring of its temporal changes. None of the currently available identification techniques are able to visualize a “complete” community, whereas techniques designed for analyzing bacterial ecosystems generally display limited or labor-intensive identification potential. This paper describes the optimization and validation of a nested-PCR-denaturing gradient gel electrophoresis (DGGE) approach for the species-specific analysis of bifidobacterial communities from any ecosystem. The method comprises a Bifidobacterium-specific PCR step, followed by purification of the amplicons that serve as template DNA in a second PCR step that amplifies the V3 and V6-V8 regions of the 16S rRNA gene. A mix of both amplicons is analyzed on a DGGE gel, after which the band positions are compared with a previously constructed database of reference strains. The method was validated through the analysis of four artificial mixtures, mimicking the possible bifidobacterial microbiota of the human and chicken intestine, a rumen, and the environment, and of two fecal samples. Except for the species Bifidobacterium coryneforme and B. indicum, all currently known bifidobacteria originating from various ecosystems can be identified in a highly reproducible manner. Because no further cloning and sequencing of the DGGE bands is necessary, this nested-PCR-DGGE technique can be completed within a 24-h span, allowing the species-specific monitoring of temporal changes in the bifidobacterial community.


2017 ◽  
Vol 5 (1) ◽  
pp. 72-80
Author(s):  
Umesh Prasad Shrivastava

The rhizobacteria were isolated from rhizosphere of rice plant of different fields of 4 districts of Nepal and 5 districts of Bihar and Uttar Pradesh, adjoining states of India with Nepal. The DGGE analysis was performed for diversity analysis. For the construction of dendrogram, 16S rRNA gene was amplified by two different sets of primers. The DGGE ladder consisting of PCR amplified products of nine pure bacterial cultures were obtained. The first DGGE ladder was prepared by 400 bp fragment of 16S rDNA with GC clamp and the second DGGE ladder was prepared with 200 bp fragment of 16S rDNA with GC clamp. The perpendicular DGGE of these amplicons based on their melting behavior clearly demonstrated separation of different isolates. The 16S rDNA fragment amplified with primer set of V2-V3 regions with GC clamp showed separation between 40-60% of denaturant. The DGGE profile based on primer set F352T and 519r for various bacteria present in soil samples of 5 districts of India and 4 districts of Nepal revealed that the number of bands which might be specific for diazotrophic isolates varied from 2 to 11. The dendrogram constructed based on DGGE profile of various samples of 5 districts of India and 4 districts of Nepal showed that all the samples could be clustered in nine groups with 58-96% similarity to each other. Among all these 37 samples, only Var-4 and Var-5 showed 100% similarity, no other samples from any site showed 100% similarity. Int. J. Appl. Sci. Biotechnol. Vol 5(1): 72-80


2011 ◽  
Vol 77 (16) ◽  
pp. 5770-5781 ◽  
Author(s):  
Yanhong Chen ◽  
Gregory B. Penner ◽  
Meiju Li ◽  
Masahito Oba ◽  
Le Luo Guan

ABSTRACTOur understanding of the ruminal epithelial tissue-associated bacterial (defined as epimural bacteria in this study) community is limited. In this study, we aimed to determine whether diet influences the diversity of the epimural bacterial community in the bovine rumen. Twenty-four beef heifers were randomly assigned to either a rapid grain adaptation (RGA) treatment (n= 18) in which the heifers were allowed to adapt from a diet containing 97% hay to a diet containing 8% hay over 29 days or to the control group (n= 6), which was fed 97% hay. Rumen papillae were collected when the heifers were fed 97%, 25%, and 8% hay diets. PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR analysis were used to characterize rumen epimural bacterial diversity and to estimate the total epimural bacterial population (copy numbers of the 16S rRNA gene). The epimural bacterial diversity from RGA heifers changed (P= 0.01) in response to the rapid dietary transition, whereas it was not affected in control heifers. A total of 88 PCR-DGGE bands were detected, and 44 were identified from phyla includingFirmicutes,Bacteroidetes, andProteobacteria. The bacteriaTreponemasp.,Ruminobactersp., andLachnospiraceaesp. were detected only when heifers were fed 25% and 8% hay diets, suggesting the presence of these bacteria is the result of adaptation to the high-grain diets. In addition, the total estimated population of rumen epimural bacteria was positively correlated with molar proportions of acetate, isobutyrate, and isovalerate, suggesting that they may play a role in volatile fatty acid metabolism in the rumen.


2013 ◽  
Vol 726-731 ◽  
pp. 898-901
Author(s):  
Ri Na Wu ◽  
Xiao Meng Pang ◽  
Xi Yan Wang ◽  
Jun Rui Wu

Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA gene has been regarded as one of powerful tools for gaining insight into the bacterial diversity of intestinal system. In the present study, hyperlipidemia model was constructed in rat according to the tests of blood lipids. Fecal samples of rats were collected after 60d feeding, and DGGE was used to investigate the diversities of intestinal bacteria in the artificially-induced hyperlipidemia rats and normal rats. The results showed that two patterns had similarities, but there were also some different bacteria communities. Moreover, control group had much more bands than model group on gel, showing species in intestinal of model rats might be deduced by hyperlipidemia. It will be helpful to explore the relationship between hyperlipidemia and intestinal flora.


2010 ◽  
Vol 9 (46) ◽  
pp. 7891-7899 ◽  
Author(s):  
Islam ud din ◽  
Khan Sardar ◽  
El latif Hesham Abd ◽  
Ahmad Ayaz ◽  
Houbo Su ◽  
...  

2002 ◽  
Vol 48 (7) ◽  
pp. 611-625 ◽  
Author(s):  
Madhukar B Khetmalas ◽  
Keith N Egger ◽  
Hugues B Massicotte ◽  
Linda E Tackaberry ◽  
M Jill Clapperton

To assess the effect of fire and salvage logging on the diversity of mycorrhizal–bacterial communities, bacteria associated with Cenococcum, Thelephora, Tomentella, Russulaceae, and E-strain ectomycorrhizae (ECM) of Abies lasiocarpa seedlings were characterized using two approaches. First, bacteria were isolated and characterized by Biolog©, gas chromatography fatty acid methyl ester (GC-FAME), and amplified 16S rDNA restriction analysis (ARDRA). The bacterial communities retrieved from ECM from both sites were dominated by Proteobacteria (groups gamma and beta). Pseudomonas was the most common genus isolated, followed by Variovorax, Burkholderia, and Xanthomonas. Gram-positive isolates (mostly high-G+C Gram-positive bacteria) were more frequently retrieved on the burned-salvaged site, many commonly associated with the two ascomycete ECM, Cenococcum and E-strain. Pseudomonas species were retrieved more frequently from Thelephora. Although actinomycetes were isolated from all sites, almost no actinomycetes or other Gram-positive bacteria were isolated from either Thelephora or Tomentella. Second, amplified 16S rRNA gene sequences were amplified directly from root tips and then cloned into the plasmid vector pAMP1, followed by restriction analysis. This technique distinguished more genotypes than isolates retrieved by culturing methods, but generally, results were similar in that the largest proportion of the bacteria were putatively Gram-negative; putative Gram-positive bacteria were fewer and most were from the burned–salvaged site. Direct cloning resulted in many patterns that did not match any identified isolates, suggesting that a large proportion of clones were unique or not culturable by the methods used. Analysis for both protocols showed no significant difference in bacterial diversity between the burned–salvaged and unburned sites. Key words: rhizosphere bacteria, ARDRA, 16S rDNA, Biolog©, GC-FAME.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Remy Villette ◽  
Gaelle Autaa ◽  
Sophie Hind ◽  
Johanna B. Holm ◽  
Alicia Moreno-Sabater ◽  
...  

AbstractHigh-throughput phylogenetic 16S rRNA gene analysis has permitted to thoroughly delve into microbial community complexity and to understand host-microbiota interactions in health and disease. The analysis comprises sample collection and storage, genomic DNA extraction, 16S rRNA gene amplification, high-throughput amplicon sequencing and bioinformatic analysis. Low biomass microbiota samples (e.g. biopsies, tissue swabs and lavages) are receiving increasing attention, but optimal standardization for analysis of low biomass samples has yet to be developed. Here we tested the lower bacterial concentration required to perform 16S rRNA gene analysis using three different DNA extraction protocols, three different mechanical lysing series and two different PCR protocols. A mock microbiota community standard and low biomass samples (108, 107, 106, 105 and 104 microbes) from two healthy donor stools were employed to assess optimal sample processing for 16S rRNA gene analysis using paired-end Illumina MiSeq technology. Three DNA extraction protocols tested in our study performed similar with regards to representing microbiota composition, but extraction yield was better for silica columns compared to bead absorption and chemical precipitation. Furthermore, increasing mechanical lysing time and repetition did ameliorate the representation of bacterial composition. The most influential factor enabling appropriate representation of microbiota composition remains sample biomass. Indeed, bacterial densities below 106 cells resulted in loss of sample identity based on cluster analysis for all tested protocols. Finally, we excluded DNA extraction bias using a genomic DNA standard, which revealed that a semi-nested PCR protocol represented microbiota composition better than classical PCR. Based on our results, starting material concentration is an important limiting factor, highlighting the need to adapt protocols for dealing with low biomass samples. Our study suggests that the use of prolonged mechanical lysing, silica membrane DNA isolation and a semi-nested PCR protocol improve the analysis of low biomass samples. Using the improved protocol we report a lower limit of 106 bacteria per sample for robust and reproducible microbiota analysis.


2007 ◽  
Vol 19 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Xiang Xiao ◽  
Mingguang Li ◽  
Ziyong You ◽  
Fengping Wang

Both bacterial culture and molecular approaches were used to investigate the bacterial diversity inside the Chinese Antarctic Great Wall Station and in its adjacent area. Heterotrophic bacteria were isolated from the samples using a direct plating method. γ-Proteobacteria, Actinobacteria, Flavobacteria and Firmicutes were isolated from these samples. In the three water samples, Pseudomonas species were dominant. In soil samples, Flavobacterium, Bacillus or Arthrobacter species dominated. Escherichia coli strains were isolated only in two samples from inside the station. Total cell counts in the six soil samples were semi-quantified by Quantitative Competitive-PCR of the 16S rRNA gene copies. The soil samples contained 105 to 109 cells g−1. Denaturing gradient gel electrophoresis (DGGE) was used further to investigate the bacterial diversity in the soil samples. A wider range of bacterial diversity including α-Proteobacteria, β-Proteobacteria, δ-Proteobacteria, γ-Proteobacteria, Flavobacteria, Actinobacteria and unclassified bacteria was discovered.


2018 ◽  
Author(s):  
Shinichi Kai ◽  
Yoshiyuki Matsuo ◽  
So Nakagawa ◽  
Kirill Kryukov ◽  
Shino Matsukawa ◽  
...  

AbstractRapid identification of bacterial pathogens is crucial for appropriate and adequate antibiotic treatment, which significantly improves patient outcomes. 16S ribosomal RNA (rRNA) gene amplicon sequencing has proven to be a powerful strategy for diagnosing bacterial infections. We have recently established a sequencing method and bioinformatics pipeline for 16S rRNA gene analysis utilizing the Oxford Nanopore Technologies MinION™ sequencer. In combination with our taxonomy annotation analysis pipeline, the system enabled the molecular detection of bacterial DNA in a reasonable timeframe for diagnostic purposes. However, purification of bacterial DNA from specimens remains a rate-limiting step in the workflow. To further accelerate the process of sample preparation, we adopted a direct PCR strategy that amplifies 16S rRNA genes from bacterial cell suspensions without DNA purification. Our results indicate that differences in cell wall morphology significantly affect direct PCR efficiency and sequencing data. Notably, mechanical cell disruption preceding direct PCR was indispensable for obtaining an accurate representation of the specimen bacterial composition. Furthermore, 16S rRNA gene analysis of mock polymicrobial samples indicated that primer sequence optimization is required to avoid preferential detection of particular taxa and to cover a broad range of bacterial species. This study establishes a relatively simple workflow for rapid bacterial identification via MinIONTMsequencing, which reduces the turnaround time from sample to result, and provides a reliable method that may be applicable to clinical settings.


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